Wind energy conversion system (WECS) is a stochastic system, since wind speed varies intermittently. Therefore a non-linear autoregressive moving average with exogenous input (NARMAX) model is developed to represent the dynamics of WECS which is used for real-time implementation. In a doubly-fed induction generator (DFIG) WECS, speed and power are the outputs for regulation which are achieved by controlling the torque and pitch angle, repetitively. NARMAX model identifies the structure and significant terms of speed and power of DFIG WECS and its parameters are estimated employing an on-line adaptive recursive least squares algorithm. For optimisation of torque and pitch angle, performance index (PI) is defined in non-linear adaptive model predictive controller (NAMPC) to achieve the control objective, i.e. torque and pitch angle. The weights in PI are updated until the optimised values in control inputs (torque and pitch control) are achieved. Boundedness of the WECS is defined by considering the constraints on the outputs and control inputs. Extensive simulations are carried out with NARMAX structure with NAMPC on DFIG WECS using MATLAB/SIMULINK and the performance is compared with conventional proportional–integral controller and model predictive control. From the obtained results, it is observed that the NARMAX model with NAMPC has minimum deviations from the operating point in power, speed, torque and pitch angle compared to other controllers.

Serial-in encoders for quasi-cyclic low-density parity-check (QC-LDPC) codes are widely used. To provide flexible interfaces and reduce complexity, three parallel-in QC-LDPC encoders are proposed. One consists of shift-register–adder–accumulator (SRAA) circuits, the others consist of rotate-left-accumulator (RLA) circuits. It is shown that a partially parallel-in encoder is comparable to or even superior to a serial-in one based on the same circuits; an RLA-based encoder is preferable to a SRAA-based one with the same speed, whether they are partially parallel-in or fully parallel-in.

The authors propose a wideband monopole antenna that is tightly aligned to one edge of its ground plate. Wideband impedance matching with fractional bandwidth of ∼93% is attained by varying stepwise the lateral alignment of the monopole and the ground plate so that the feed side of monopole partially overlaps the ground plate. The tight alignment and overlap concentrates a part of the electric field such as a travelling wave. The step structure rotates the electric field so that the concentrated electric field in the feed side orients roughly the same direction with the electric field in the tip side which is converted into radiation. The basic antenna characteristics are examined by simulation, and verified in experiments.

In this study, a full automatic technique has been presented to assist physicians in early detection of breast cancer based on different degrees. First the region of interest is determined using full automatic operation and the quality of image is improved. Then, some features including statistical, morphological, frequency domain, histogram and grey-level co-occurrence matrix features are extracted from segmented right and left breasts. Subsequently, to achieve the best features and increase the accuracy of the proposed method, feature selectors such as minimum redundancy and maximum relevance, sequential forward selection, sequential backward selection, sequential floating forward selection, sequential floating backward selection and genetic algorithm have been used. Finally, to classify and TH labeling procedures, supervised learning techniques such as AdaBoost, support vector machine, nearest neighbor, Naïve Bayes and probability neural network are applied and compared with each other. The results obtained on native database showed the significant performance of the proposed algorithm in comprising to the similar studies. The experimental results gave the best mean accuracy of 88.03% for only using 0° image with combination of mRMR and AdaBoost and for combination of 3 degrees with combination of GA and AdaBoost.

It seems a good idea to place the relay coil in the middle to maximise the load voltage in a 3-coil wireless power transfer system; however, no literature points out clearly the reason and the necessary conditions that it holds. In this study, the complex relationship between coupling coefficients and distances is approximated by a simple polynomial, and then a rigorous analysis is carried out to show clearly that the optimal relay coil position of a 3-coil wireless power transfer system is just the middle of the drive loop and the load loop under the symmetrical condition that coil quality factors of the drive loop and the load loop are equal, and furthermore the middle is not the optimal position if the symmetrical condition is destroyed. Finally, the theoretical results are confirmed by the physical experiments.

Fault estimation problem for linear multi-agent systems with undirected graphs is studied. A two-layer observer based on the relative measured output information is proposed, and specially it utilises the transformation of relative output rather than the absolute one. The integral action is used to construct an adaptive fault estimator for improving the estimation performance. The fault estimation is introduced back into the observer so that fault estimation problem can be considered as stabilisation problem of the observer error dynamics. Finally, simulations are undertaken for validating the effectiveness of the theoretical results.

In this study, three different parameter extraction approaches for GaN high electron mobility transistors are presented and evaluated. The first approach depends on only cold pinch-off measurements, the second approach based on cold pinch-off and forward measurements and the last one uses de-embedding open structure in addition to unbiased cold measurements at VDS = 0 V and VGS = 0 V. The extracted values using the first two methods have a very good agreement with the extracted values using the last mentioned procedure. This study results verify the applicability of using either pinch-off measurements or cold unbiased measurements with open structure to extract the device parasitic elements. This accordingly will reduce the cost of using extra de-embedding structures or high-current stress forward measurements.

Al microtubes were fabricated by electromigration and controlled etching. Samples consisted of thin Al films with slits and discharge holes near the anode. Al atoms accumulated and discharged forming a microwire, which was then etched into a hollow microtube. Al microtubes could be fabricated at predetermined positions, with their lengths dependent on the current supply duration. The outer and inner diameters of the Al microtube could be determined by controlling the size of the etched hole. This technique has potential in the fabrication of other metallic microtubes.

The reactive power in non-sinusoidal circuits is determined here from an energy analysis instead of using the non-sinusoidal apparent power S. In the first of the two energy analyses, circuits previously examined by the currents’ physical components power theory are re-examined using the principle of conservation of energy, the balance principle of the reactive power and the concept of reactive power compensation. This energy analysis yields a reactive power value substantiated by the aforementioned principles and power theory but it also suggests a value of S that differs from its traditional definition. The energy analysis performed with the circuit analysis technique based on geometric algebra, its GN domain power theory and M, a conservative power quantity based on the flow of energy, confirms the reactive power value attained in the former analysis. More importantly, M clarifies three intriguing issues about S: its value, its physical significance and whether this quantity can lead to erroneous conclusions. These, and previous results, demonstrate that the reactive power should be assessed on the energy flow but a multidimensional mathematical framework is needed to better understand energy flow in non-sinusoidal circuits.